Oil distillation



J. s. WALLIS 2,030,485

OIL DISTILLATION Filed Deo. 5, 1930 Feb. l1, 1936..

2 Sheets-Sheet l I l u Z TVE TOR i WW1' MM Feb. 1l, 1936. J 5 WALLlS2,030,485

OIL DISTILLATION Filed Deo. 5, 1930 2 Sheets-Sheet -2 fill 36 f 34brface fonde/75er 36 36 gi/Sieg 46 f 46 Patented Feb. 11, 1936 UNITEDSTATES PATENT OFFICE to Foster Wheeler Corporation, New York,

N. Y., a corporation of New York Application December 3, 1930, SerialNo'. 499,624

20 Claims.

My invention relates to oil rening apparatus.

I-Ieretofore it has been the practice in this art to make separatepieces of equipment for the vapor heat exchanger to which overheadvapors are conducted from a fractionating tower, the surface condenserto which the oil vapor next passes, the separator in the hot well of thevapor condenser, the barometric condenser for condensing the water vaporwhich leaves the tower with the oil vapor, and the vacuum run-down tankwhich receives the separated and liqueiied oil. This necessitatesseparate supporting steel structure, many connecting conduits, largespace requirements and the accompanying expense necessitated by buildingseparate items and the connection of these items into a system.

One of the objects of the present invention is to combine the heatexchanger, the surface condenser, the separator, the barometriccondenser and the run-down tank all in a single unit, preferably avertically disposed cylindrical drum. The combination of all theseheretofore separate units in a single unit results in less supportingsteel structure, less connecting conduits, less space requirements andis much cheaper. Furthermore, heat losses can be avoided and the dangerof air leakage at high vacuum is reduced to a minimum.

Another object of my invention is to minimize the length of conduitbetween a fractionating tower and the apparatus or apparatuses fortreating the oil vapor after its leaves the tower. By reducing thelength of conduit I reduce the amount of expansion and contraction forwhich provision must be made. In the ordinary tower of the bubble traytype there are lateral portions of the bubble trays which are relativelyineffective. I eliminate these lateral portions or some of them as partof the bubble trays and provide one or more passages inside the towerlaterally of the bubble trays for conducting overhead vapor downwardlywithin the tower to an intermediate point from which one or moreconduits lead to the apparatus or apparatuses for subsequent .treatment.This also saves length of conduit and supporting steel work.

Further obj ects and advantages of my invention will be apparent fromthe following description considered in connection with the accompanyingdrawings, which are to be considered a part of this specication.

Fig. l is a view, partly in cross-section, of a preferred embodiment ofmy invention showing a fractionating tower in connection with my im.-proved combined unit;

Fig. 2 is a cross-sectional View taken on the line 2-2 of Fig. l;

Fig. 3 is a cross-sectional view of a portion of the fractionating towershown in Fig. 1 but seen at right angles to the view shown in Fig. 1 andtaken on the line 3-3 of Fig. 2;

Fig. 4 is a cross-sectional view of a preferred embodiment of thecombined unit;

Fig. 5 is a cross-sectional view of the combined unit shown in Fig. 4but seen at an angl-e of 90 degrees from the view in Fig. 4 and taken onthe line 5-5 of Fig. 4;

Fig. 6 is a cross-sectional view taken on the line 6-6 of Fig. 4;

Fig. 'l is a cross-sectional view taken on the line 'I-l of Fig. 4; and

Fig. 8 is a cross-sectional View taken on the line 8-8 of Fig. 4.

Referring more particularly to Fig. l, reference character I0 designatesa vacuum fractionating tower, the shell of which consists of a verticalcylindrical steel shell. An oil supply conduit II communicates with alower portion of the tower, as shown. The tower below the point ofcommunication of conduit II is of reduced cross-section as compared withthat portion of the tower above and is provided with a series of bubbletrays I2. Above conduit II there is located within the tower a series ofbaies I3 above which is a stripping section I4. Above stripping sectionI4 are a series of bubble trays I5, a stripping section I and anotherseries of bubble trays Il. A by-pass conduit 9 having a valve 8 thereinis provided around each of the stripping sections and, if Valve 8 isopen, serves to convey liquid from the bubble tray above the strippingsection, around the section and ontol the tray next below. All of thesebubble trays I2, I5, and Il may be of similar type and comprise a trayportion I8 having central vapor passages I9 over which are bubble caps2B having depending edges. Downflow conduits 2| serve to convey liquidfrom one bubble tray to the next. The stripping sections may be of anypreferred design and comprise a member 2,2 secured to the interior oftower I0 and pro- 45 vided with a vertical flange 23 which forms a vaporpassageway through the stripping section. The stripping section is thepocket dened by member 22, with flange 23 and the adjacent portion ofthe tower. Side streams may be with- 50 drawn from stripping sections I4and IB through conduits 24 and 25, respectively, which convey the liquidcollected at the stripping sections from the tower. A pump may beinserted in each of these conduits in order to force the liquid out ofthe 55 til tower against vacuum existing within the tower. A conduit 26is supplied with superheated steam and in turn supplies this steam tobranch conduits 21 and 28 which in turn distribute it within thestripping sections I4 and I6,respectively. The branch conduit 29supplies superheated steam to the lower part of tower I0. A conduit 36communicates with the bottom of the tower and conveys bottoms therefrom.

Some of the bubble trays, comprising the groups I5 and I1, are formedwith straight edges to leave segment-shaped spaces between the trays andthe interior of the tower shell. Member 22 defining stripping section I6is formed in similar manner. Vertical plates 3I are secured within thetower with each vertical edge in contact with the cylindrical interiorof the tower shell and with their inner surfaces in contact with andpreferably secured to the straight edges of the bubble trays and ofmember 22. There are thus formed between the cylindrical shell of towerI and plate 3| segment-shaped, vertically extending passageways 32 whichare open at the top and closed at the bottom by side extensions I a, ofone of the bubble trays. Obviously the closing members for the bottomsof passageways 32 may be separate segment-shaped pieces and independentof the bubble trays.

While I have shown two passageways 32 it will be understood that theremay be one or more of these passageways. Conduits 33 communicate withthe bottom of passageways 32 and lead to opposite sides of the morecentral portion of a shell 34 which houses the combined heat exchanger,surface condenser, barometric condenser, and run-down tank. Conduits 33open into a chamber 35 formed between vertical plates 36 which areplaced within shell 34 vin a manner similar to that in which plates 3i,were placed Within the tower IU. The top of chamber 35 is closed bymeans of a plate 31. Within chamber 35 below th'e point of entrance ofconduit 33 is located a bank of tubes 38 which constitute a heatexchanger.

The heat exchanger comprises an inlet header 39 and an outlet header 40between which extend the tubes 38. These headers are secured to shell 34in any suitable way, as by iiange members 4I. Below heat exchanger tubes38 is a bank of surface condenser tubes 42 which extend between an inletheader 43 and an outlet header 44 in a manner similar to that describedin connection with the heat exchanger.

Chamber 35, as defined by walls 36 extends some distance below the bankof condenser tubes 42 and there terminates in an open bottom, whichcommunicates with the lower portion of shell 34, hereinafter referred toas vacuum run-down portion 45. The vertical plates 36 form a pair ofsegment-shaped passageways 46 between the plates and the interior ofshell 34. These passageways are open at both the bottom and the top.

A conduit 41 supplies cooling water for the barometric condenser to adistributing device 48 which is located in the upper part of shell 34.Distributing device 48 comprises a cone-shaped member having ahorizontal flange 49, the periphery of which contacts shell 34, and avertical ange 50. Secured to flange 56 is a horizontal annular ring 5Iprovided with a series of apertures 5Ia. Below distributing device 48within shell 34 is a battle and re-distributing device 52 whichcomprises a tray 53 formed with a series of apertures therethrough.Supported above tray 53 by means of members 54 is a cover plate 55,likewise provided with apertures. 'Ihe apertures in cover plate 55 andin tray 53 are not in alignment. Re-distributing device 52 extends theentire distance across the tower as viewed in Fig. 5 but as viewed inFig. 4 there are passageways 56 left between the sides of the1re-distributing device and the shell 34. Below re-distributing device52 is a bafe and re-distributing device 51 through the central part ofwhich' is a passageway 5B. Ete-distributing device 51 is similar todevice 52 insofar as it comprises a tray 53 which has apertures 59a,formed therein and covered by cover plates 613 which are provided withapertures 66a out of alignment with the apertures in tray 53. Belowre-distributing device 51 is a liquid receiver 6I which may be formed byhori- Zontal plate 31 in conjunction with an extended portion ofvertical plates 36 and the shell 34. A conduit 62 communicates withliquid receiver 6I and extends downwardly a distance suiicient to hold acolumn of liquid corresponding to the vacuum maintained and preferablyat least thirty-two feet and discharges into a well 63.

A conduit 64 communicates with the upper part of shell 34 and leads to avacuum producing device, such as a steam jet vacuum pump 69. A conduit65 leads from the vacuum run-down portion of shell 34 and communicateswith the upper part of vacuum fractionating tower I3. A reux pump (notshown) is placed in this conduit in order to cause flow of liquidtherethrough. A conduit 66 leads from the bottom of the vacuum run-downportion 45 to storage. A oat 61 operatively connected to a valve 68serves to maintain a minimum quantity of liquid in the vacuum rundownportion of the shell. The float is arranged to close valve 68 when thelevel falls to a predetermined minimum.

The operation of the above described device is as follows:

Crude oil from storage or other source of supply is introduced intotubes 38 of the heat exchanger through inlet header 33 and passestherefrom through outlet header 43. In its passage through tubes 33 theoil is heated somewhat. The warm oil discharged from outlet header 4Q isconveyed to any suitable heater such as a tube still, where it is heatedto the desired temperature and thence passed through conduit I I to theinterior of vacuum fractionating tower I6, or it may rst pass into anatmospheric iractionating tower, the bottoms from which are then passedinto vacuum fractionating tower I 0 through the conduit II. Any mode ofheating the oil may be used. The oil may even be introduced directlyinto the tower and heated therein. There is also supplied to tower I0superheated steam through conduit 26 and branch conduits 21, 28, and 29.This superheated steam reduces the partial pressure of the oilintroduced into the tower and causes vaporization of a portion thereof.The oil vapor and superheated steam pass upwardly through the bubbletrays I5 and I 1 and the oil vapor is acted upon and partially condensedby reflux liquid supplied through conduit 65. This liquid passesdownwardly from one bubble tray to the next through down-flow conduits2l and portions thereof are removed as side streams through conduits 25and 24 from stripping sections I6 and I4, respectively, in a well knownmanner.

A portion of the oil remains in vapor form when it reaches the top oftower I0 and this oil vapor mixed with steam passes downwardly throughpassageways 32 formed between vertical plates 3| and the sides of thetower. The vaporous mixture passes from passageways 32 through conduits33 to within chamber 35 formed within shell 34 by vertical plates 35.The vaporous mixture passes downwardly through chamber 35 and comes incontact with heat exchanger tubes 38. Here the mixture is cooledsomewhat, at the same time heating the oil passing through tubes 38. Thevaporous mixture of oil and steam continues downwardly through chamber35 and comes in contact with surface condenser tubes 42 through whichflows cooling water. A further reduction in the temperature of themixture takes place at this point which results in the condensation ofthe oil vapor but not in the condensation of the steam. The liqueed oildrops out of the bottom of chamber 35 and is collected in the vacuumrun-down portion i5 at the bottom of shell 34. The steam passes out ofthe bottom of chamber 35 and thence upwardly through passageways 46formed between plates 35 and shell 34.

Cooling water is supplied to distributing device 48 through conduit 47and passes' through the apertures formed in plate 5i and falls as acylindrical curtain of water onto redistributing device 52. Here itstrikes cover plate 55 and passes through the apertures formed thereinand through the apertures formed in tray 53 which are so arranged as toproduce a curtain of water on either side of the shell, which strikesre-distributing device 59. Re-distributing device 55 likewise causes thewater to fall in a curtain on either side of the shell into receiver 5i,from which it passes through conduit 62 to well 53. The steam issuingfrom the upper ends of passageways 45 is caused to pass in a tortuouspath through aperture 58 in baiiie 5l and around the re-distributingdevice 52 and hence passes through the curtains of water produced bythese devices and is thereby condensed. Non-condensable gases, such asair, which are introduced into shell 34 are withdrawn therefrom throughconduit 54 by a steam jet vacuum pump 35 or the like, which serves tomaintain a vacuum within shell 34 and also within vacuum fractionatingtower l5. Ine asmuch as the vertical distance between liquid receiver 6|and well 33 is suiiicient to give a great enough head of water toovercome the vacuum Within the shell, the water will ow from receiver 6lby gravity against the difference in pressure resulting from the vacuummaintained within the tower.

The oil collected in the vacuum run-down portion 45 of shell 34 passestherefrom through conduits 65 and 63, Tl'ie oil withdrawn throughconduit 65 is introduced into the upper part of tower l0 and serves asreflux liquid while the oil withdrawn through conduit 55 isI passed tostorage. Float 6'! maintains a minimum liquid level by regulating therate of dischargev of oil through conduit 66.

Thus it will be seen that I have combined in a novel manner at leastfour units, which heretofore have been separate units, into a singlestruc* ture. Furthermore, I have greatly reduced the length of theconduit for conveying Vapor from the fractionating tower. If this vaporconduit communicated with the upper 'part of the tower shown in Fig. 1,it will be seen` that i't would be necessary to provide a conduitseveral times as long as are the vapor conduits 33 which I am able touse because of my invention.

While I have shown and described a preferred embodiment of my inventionit is `to be understood that modifications thereof which are apparent toa person skilled in the art fall within its scope, which is to belimited only by the appended claims viewed in the light of the priorart.

What I claim is:

l. Apparatus for separately condensing and collecting oil vapors andsteam from a mixture of the same, comprising a shell, means forintroducing a mixture of oil vapors and steam into the shell, means forcondensing the oil vapors from the mixture, means for collecting the oilcondensate in the shell, a plurality of trays in the shell, means forintroducing water onto one of the trays, means for distributing thewater and causing it to flow in a curtain between at least two of thetrays and through which` curtain the steam from said mixture is adaptedto pass and be condensed thereby, means for collecting the water andsteam condensate in the shell out of contact with the oil condensate andmeans for withdrawing the water and steam condensate from the shell.

2. Apparatus for separately condensing and collecting oil vapors andsteam from a mixture of the same, comprising. a shell, means forintroducing a mixture of oil vapors and steam into the shell, means forcondensing the oil vapors from the mixture, means for collecting the oilcondensate in the shell, a plurality of trays in the shell, means forintroducing water onto the uppermost of said trays, means fordistributing the water to cause it to ow in a curtain between saidtrays, said trays being arranged and disposed so as to cause the steamfrom said mixture to How through said curtains of water to therebycondense the steam, means below said trays for collecting the water andsteam condensate and means for withdrawing the water and steamcondensate from the shell.

3. Apparatus of the character described comprising a shell, means formaintaining a vacuum in the shell, a chamber in the shell, means forintroducing a mixture of oil vapors and steam into the chamber, a heatexchanger in the chamber for cooling the vapors, a condenser in thechamber for condensing the oil vapors from the mixture, means forcollecting the oil condensate in the shell, means for withdrawing theoil condensate from the shell, a plurality of trays in the shell, meansfor introducing water onto the uppermost of the trays, means associatedwith the trays for causing the water to flow in a curtain between saidtrays, a passageway between the chamber and the shell through whichsteam is adapted to flow from said chamber to said trays, said traysbeing arranged and disposed to cause the steam to flow in a circuitouspath through the curtains of water to thereby condense the steam, acollecting tray below said trays for collecting the water and steamcondensate and means for withdrawing the water and steam condensate fromsaid tray.

4. Apparatus for separately condensing and collecting oil vapors andsteam from a mixture oi the same, comprising a shell having an inlet fora mixture of oil vapors and steam, oil vapor condensing means in theshell below the inlet, means causing said mixture to flow downwardlyinto Contact with said condensing means to thereby condense the oilvapors from the mixture, means below the condensing means for collectingthe condensate of the oil vapors in the shell, a steam condenser in theshell above the inlet, means causing the steam from said mixture to flowinto contact with the steam condenser to condense the steam, and meansin the shell below the steam condenser for collecting the steamcondensate out of contact with the oil vapor condensate.

5. Apparatus for separately condensing and collecting oil vapors andsteam from a mixture of the same, comprising a shell having an inlet fora mixture of oil vapors and steam, means for maintaining a vacuum in theshell, oil Vapor condensing means in the shell below the inlet, meanscausing said mixture to ilow downwardly into contact with saidcondensing, means to thereby condense the oil vapors from the mixture,means below the condensing means for collecting the condensate of theoil vapors in the shell, a steam condenser in the shell above the inlet,means causing the steam from said mixture to flow into contact with thesteam condenser to condense the steam, and means in the shell below thesteam condenser for collecting the steam condensate out of contact withthe oil vapor condensate.

6. Apparatus for separately condensing and collecting oil vapors andsteam from a mixture of the same, comprising a shell having an inlet fora mixture of oil vapors and steam, a heat exchanger in the shell belowthe inlet, means causing said mixture to flow downwardly into contactwith the heat exchanger to thereby cool the mixture, oil vaporcondensing means in the shell below the heat exchanger, means causingsaid cooled mixture to ilow into contact with said condensing means tothereby condense the oil vapors from the mixture, means below the heatexchanger for collecting the condensate of the oil vapors in the shell,a steam condenser in the shell above the inlet, means causing the steamfrom said mixture to flow into contact with the steam condenser tocondense the steam, and means in the shell below the steam condenser forcollecting the steam condensate out of contact with the oil vaporcondensate.

7. Apparatus for separately condensing and collecting oil vapors andsteam from a mixture of the same, comprising a shell having an inlet fora mixture of oil vapors and steam, oil vapor condensing means in theshell below said inlet, means causing said mixture to flow into Contactwith said condensing means to thereby condense the oil vapors from themixture, means below said condensing means for collecting the condensateof the oil vapors in the shell, a steam condenser in the shell abovesaid inlet, means causing the steam from said mixture to flow intocontact with the steam condenser without again coming into contact withthe oil vapor condensing means to condense the steam, and means in theshell below the steam condenser for collecting the steam condensate outof contact with the oil vapor condensate.

8. An apparatus for condensing mixtures of hydrocarbon Vapor and thelike comprising a vertical shell, a cooling unit within said shell,means for introducing hydrocarbon vapor above said cooling unit andmeans for directing the vapor downwardly over the unit to the lowerportion of the shell and upwardly to the upper portion of the sameindependently of the downilowing vapor.

9. An apparatus for condensing hydrocarbon vapor and the like comprisinga vertical shell, a cooling unit transversely disposed within saidshell, means for introducing hydrocarbon vapor above said cooling unit,means for directing the Vapor downwardly over the unit to the lowerportion of the shell, and for directing vapor fro-1n the said lowerportion of the shell to the upper portion of the same independently ofthe downflowing vapor, the lower portion of the shell serving as acondensate receiver and condensing means disposed at the upper part ofsaid shell.

l0. An apparatus for condensing vaporized hydrocarbons and the like,comprising a vertical shell, a plurality of heat exchangers removably.7positioned in said shell, a baille partially surrounding said heatexchangers and forming a hood having its lower portion open andextending downwardly into the lower portion of said shell, said lowerportion of the shell forming a receiver for the condensate andpermitting it to collect in a pool, means for withdrawing the condensatefrom said pool, means for introducing vaporized hydrocarbons and thelike into said hood forming baille, and means disposed above said heatexchangers adapted to condense the uncondensed portions of saidvaporized hydro-- carbons.

11. A condenser as in claim l0, wherein said hood forming baille isspaced inwardly of said shell to form a passage for the uncondensedvapors leading to said condensing means.

l2. A condenser as in claim l0, in which a. condensate receiving meansis disposed below said condensing means', an outlet for the condensate,and an outlet for the uncondensed portions of the vapors.

13. An apparatus for condensing hydrocarbon vapors and the likecomprising in combination. a. shell, an inverted baille within the shellin spaced relation therewith, condenser tubes extending through saidbaille and means for introducing hydrocarbon vapors and the like intosaid baille.

14. An apparatus for condensing hydrocarbon vapor and the likecomprising a vertical shell having a vapor inlet opening, and acondensate outlet opening in its bottom portion, a cooling unit disposedwithin said shell, means for directing the ilow of vapor from said inletopening, over the cooling unit to the lower portion cf the shell and forchanging the course of the vapor at the said lower portion of the shelland directing the same upwardly at the sides of the cooling unir, to theupper portion of said shell.

15. An apparatus for condensing hydrocarbon vapor and the likecomprising a vertical shell having a vapor inlet opening, a cooling unittransversely disposed in the shell below said inlet, a baille structuredisposed so as to enclose said unit within said shell and adapted todirect the flow of vapor over said unit, said shell having a condensateoutlet opening in its lower portion below said cooling unit, and saidbaille structure providing a space between the cooling unit and theshell to permit the upward passage or vapor from the said lower portionof the shell to the upper portion of the same.

16. An apparatus for condensing hydrocarbon vapor and the likecomprising a vertical shell having a Vapor inlet opening, a. coolingunit transversely disposed in the shell below said inlet, a baffledisposed above and at the sides of said unit within said shell andadapted to direct the ilow of vapor over said unit, said shell having anoutlet opening in its lower portion below said cooling unit, said bailleproviding a space at the side of said shell to permit the upward passageof vapor from the said lower pcrtion of the shell to the upper portionof the same. and vapor condensing means disposed at the upper end ofsaid shell.

17. An apparatus for condensing hydrocarbon vapor and the likecomprising a vertical, substantially cylindrical shell having a vaporinlet opening, a cooling unit transversely disposed in the shell belowsaid inlet, the lower portion of said shell embodying a condensatereceiving zone and having an outlet c-pening for liquid condensate,baille plates disposed above and at the sides of the cooling unitadapted to direct the flow of vapor from the said inlet port over saidcooling unit, said baffles providing segmental spaces at the sides ofsaid unit permitting the upward passage of vapor from the lower portionof the shell tc the upper part of the same.

18. An apparatus for condensing hydrocarbon vapor and the likecomprising a vertical, substantially cylindrical shell, a cooling unittransversely disposed within the shell, baffling means above and at thesides of said cooling unit, means for introducing hydrocarbon vaporabove the cooling unit within said baiiles, said baiiles at the sides ofsaid cooling unit providing passageways at the sides of the saidcylindrical shell adapted to permit the passage of vapor from the lowerportion of the shell to the upper portion of the same, and condensingmeans disposed above the said upper baille.

19. An apparatus for condensing hydrocarbon vapor and the likecomprising a vertical, substantially cylindrical shell having a vaporinlet opening, a cooling unit transversely disposed in the shell belowsaid opening, the lower portion of said shell embodying a condensatereceiving zone and having an outlet opening for liquid condensate,baiiie plates disposed above and at the sides of the cooling unitadapted to direct the ow oI Vapor from the said inlet port over saidcooling unit, said bales providing segmental spaces at the sides of saidunit, permitting the upward passage of residuary uncondensed vapor fromthe lower portion of the shell to the upper part of the same, means inthe upper part of said shell above the said inlet opening for condensingthe said residuary Vapor, and means for separately withdrawing thecondensate from the receiving Zone of the shell, the condensate of theresiduary vapor, and the non-condensed vapor.

20. An apparatus for condensing hydrocarbon vapor and the likecomprising a vertical, substantially cylindrical shell, a cooling unittransversely disposed within the shell, baflling means above and at thesides of said cooling unit, means for introducing hydrocarbon vaporabove the cooling unit within said baffles, said baies at the sides ofsaid cooling unit providing passageways at the sides of the cylindricalshell, adapted to permit the upward passage of vapor from the lowerportion of the shell tothe upper portion of the same.

JOHN SAMUEL WALLIS.

